Synthesis and characterization of novel magnetic heat-resistant poly(amide-ether) nanocomposites based on dibenzo xanthene

Poly(amide-ether)/NiFe₂O₄ nanocomposites with different amounts of NiFe₂O₄ were synthesized by the solution intercalation method. Poly(amide-ether) (12) derived from dibenzo xanthene was prepared by condensation reaction of N-(3-(14H-dibenzo[a,j]xanthen-14-yl)phenyl)-3,5-diaminobenzamide (7) and 4,4′-(ethane-1,2-diylbis(oxy))dibenzoic acid (10) monomers. The poly amide-ether (PAE) was characterized by Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (¹H-NMR), ultraviolet–visible spectroscopy (UV–vis), and thermogravimetric analysis (TGA). The intrinsic viscosity of PAE in DMF solution, with a concentration of 0.01 g/dL at a temperature of 25 °C, was found to be 0.31 dL/g⁻¹. NiFe₂O₄ nanoparticles were prepared via the co-precipitation method and used for the preparation of new poly(amide-ether)/NiFe₂O₄ nanocomposites (PAEN 3% and PAEN 5%). The morphology, crystalline phase, thermal stability, and magnetization properties of the prepared nanocomposites were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), UV–vis, TGA, DSC, and vibrating sample magnetometer (VSM). The SEM measurements show that the diameter of the NiFe₂O₄ nanoparticles is about 40 nm. The XRD results indicated the formation of NiFe₂O₄ nanoparticles with cubic phase in the PAE matrix. In examining the optical properties, it has been observed that by increasing the NiFe₂O₄ nanoparticle concentration, PAEN 3% and PAEN 5% nanocomposites show a decrease in wavelength and have a blue shift of 2 and 4 nm, respectively, compared to pure PAE. The magnetic properties of the sample were showed that the sample exhibited typical ferromagnetic behavior at room temperature. Also, results of TGA measurement have shown that the incorporation of NiFe₂O₄ in a higher concentration in the PAE matrix revealed improved thermal stability when compared to the neat PAE. The results indicate that the prepared nanocomposites exhibited magnetic properties and improvement in the thermal stability compared to neat PAE.